Fix typos

02_Day/02_day_data_types.md

@@ -617,7 +617,7 @@ console.log(string.charCodeAt(lastIndex)) // t ASCII is 116
 
 ```
 
-13. *indexOf()*: Takes takes a substring and if the substring exists in a string it returns the first position of the substring if does not exist it returns -1
+13. *indexOf()*: Takes a substring and if the substring exists in a string it returns the first position of the substring if does not exist it returns -1
 
 ```js
 string.indexOf(substring)
@@ -635,10 +635,10 @@ console.log(string.indexOf('Script'))     //15
 console.log(string.indexOf('script'))     // -1
 ```
 
-14. *lastIndexOf()*: Takes takes a substring and if the substring exists in a string it returns the last position of the substring if it does not exist it returns -1
+14. *lastIndexOf()*: Takes a substring and if the substring exists in a string it returns the last position of the substring if it does not exist it returns -1
 
 ```js
-string.lastIndexOf(index)
+string.lastIndexOf(substring)
 ```
 
 ```js
@@ -801,7 +801,7 @@ console.log(typeof null)        // object
 
 ### Changing data type(Casting)
 
-- Casting: Converting one data type to another data type. We use _parseInt()_, _parsefloat()_,_Number()_, _+ sign_, _str()_
+- Casting: Converting one data type to another data type. We use _parseInt()_, _parseFloat()_, _Number()_, _+ sign_
   When we do arithmetic operations string numbers should be first converted to integer or float if not it returns an error.
 
 #### String to Int
@@ -941,7 +941,7 @@ console.log(numInt) // 9
     5 1 5 25 125
     ```
 
-9.  Use __substr__ to slice out the phase __because because because__ in the following sentence:__'You cannot end a sentence with because because because is a conjunction'__
+9.  Use __substr__ to slice out the phrase __because because because__ in the following sentence:__'You cannot end a sentence with because because because is a conjunction'__
 
 ### Exercises: Level 3